First noticed in the fall of 2013, “the blob” is about 1,000 miles in diameter and 300 feet deep. Technically called a “warm anomaly,” it got its nickname from Nick Bond, Washington’s state climatologist and the lead author of one of the new studies. Viewed on a map showing surface water temperatures off the coast, the great circular mass does indeed look like a blob.
In a newsletter published last summer, Bond noted that the blob was about 3 degrees Celsius (5 degrees Fahrenheit) warmer than is typical for the area and may have contributed to the state’s abnormally warm and dry winter.
The past winter and several more months of research confirmed Bond’s suspicion.
Bond and his colleagues found that the warm waters are caused by a ridge of high-pressure air lingering above them, rather than the standard low-pressure system that the Pacific Northwest usually sees in the winter. In normal winters, the low-pressure system helps the ocean water cool off and causes storms all along the West Coast. But the high pressure system made the ocean calmer and warmer — and as air moved landward from the warm waters, it carried heat rather than rain and snow. The West Coast’s high temperatures and dire drought, which has led to mandatory water restrictions in California, are likely attributable to this phenomenon, the researchers said.
The blob is also wreaking havoc on Pacific wildlife, the study found. Fish are appearing where they normally don’t belong, and the warmer, less nutrient-rich water is disrupting the food web. These findings coincide with a March report from the National Oceanic and Atmospheric Administration, which said that West Coast waters are becoming less biologically productive as they become warmer. The report attributed the strandings of nearly 1,500 starving sea lion pups, the decline in copepods (tiny crustaceans that support the base of the food chain) and other environmental shifts to the expanding “blob.”
But the blob and its impact on West Coast weather and wildlife are just one facet of a much larger phenomenon, according to Dennis Hartmann. He’s the author of the second study, which found that the warming waters of the northeast Pacific are tied to an anomaly in water temperatures thousands of miles away, roughly where the International Date Line and the equator intersect in the Tropics. Surface waters there have also been much warmer than usual, which heats the air above them. That air then curves northeast-ward until it reaches the West Coast.
“It’s like throwing a rock into a pond,” he said in a phone interview. “The wave eventually makes its way to the other side.”
And once it gets to the other side, the wave doesn’t stop at the coast, Hartmann found. Though the warm waters generate a high pressure system near California, Washington and Oregon, they cause cold, wet, low-pressure air in the central and eastern U.S., leading to heavy snowfall and bitterly cold winters. He calls the phenomenon the “North Pacific Mode” and says it contributed to the “Polar Vortex” winter of 2013-2014 as well as this year’s particularly brutal weather.
It’s not clear what’s causing the warming of the water in the Tropics (and the resulting weather weirdness). The “North Pacific Mode” phenomenon has been recorded before, though it’s been getting stronger since the 1980s and this occurrence is more persistent and more extreme than what’s been seen in the past, Hartmann said. It could be just another natural variation in ocean and atmosphere temperatures, similar to the El Nino-La Nina cycle. Or, if it persists and becomes stronger, it could signal a more fundamental shift.
“There might be an inkling that something special is happening but it’s hard at this point to tell,” he said.
Hartmann declined to speculate whether the phenomenon is a product of global warming. In a release from the American Geophysical Union, which publishes “Geophysical Research Letters,” Bond said that he doubts that the blob is caused by climate change — though he thinks it foreshadows the effects that climate change might have on the West Coast.
“This is a taste of what the ocean will be like in future decades,” he said.